Governor with hydraulic follow-up



April 13, 1954 J. s. DALE 2,675,2121

GOVERNOR WITH HYDRAULIC FOLLOW-UP Original Filed March 18, 1946 3Sheets-Sheet l ATTORNEYS.

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GOVERNOR WITH HYDRAULIC FOLLOW-UP Original Filed March 18, 1946 3Sheets-Sheet 2 ATTORNEYS.

April 13, 1954 s D 2,675,221

GOVERNOR WITH HYDRAULIC FOLLOW-UP Original Filed March 18, 1946 3Sheets-Sheet 3 gi ff f NY'RK :W I 5 .44 86 Q a f ,5,5

ATTORNEYS Patented Apr. 13, 1954 GOVERNOR WITH HYDRAULIC FOLLOW-UPJoseph S. Dale, Rockford, Hydraulic Controls, Inc.,

poration of Illinois 111., assignor to Dale Rockford, 111., a cor-Original application March 18, 1946, Serial No.

now Patent No. ber 16, 1951. Divided an 2,571,842, dated Octod thisapplication July 5, 1951, Serial No. 235,310

This invention relates to engine-governor mechanism; in particular, itconcerns novel apparatus for adjusting the speed control of such agovernor as a function of the load on the prime mover being controlledthereby.

This application is a division of my copending application, Serial No.655,086, filed March 18, 1946, and now Patent No. 2,571,842.

When the fuel supply to an engine is being regulated by a governor, itis often desirable, in the interest of stability, to cause the engine toslow down slightly as the load on it is increased. A slight downwardspeed adjustment as a iunction of engine load is particularly desirablein applications where several engines are being operated in parallel, toachieve equal division of the load among the various engines. The eiiectunder consideration is known in the art as speed droop.

The present invention concerns a particularly efiective, simple, andmechanically stable appa" ratus for achieving speed droop. While I haveherein shown my invention as applied to a particular type of hydraulicgovernor, my invention is not so limited. and may, by obviousmodifications, be employed with any of the familiar types of governorsusing fly weights and a speeder spring.

A specific object of my invention is to provide speed-droop mechanismcharacterized by unusual mechanical stability, particularly well adaptedfor holding its setting throughout long periods of operation.

Another object of my invention is to provide novel speed-droop mechanismfor a hydraulic governor wherein variation in engine speed may beaccomplished as a function of engine load without disturbing theoperation of the delicately balanced pilot valve which forms a criticalpart of such governors.

Still another object of the present invention is to provide aspeed-droop mechanism susceptible of convenient manual adjustmentexternally of the governor casing to any desired value of speed droopand characterized also by mechanical ruggedness and freedom from fragileparts.

Other objects and advantages of the present invention will appear as thespecification proceeds.

I have illustrated certain typical embodiments of my invention in theaccompanying drawing. In the drawing, Figure 1 is an externalperspective view of a governor embodying my invention. Figs. 2 and 2'are sectional views, the section betaken along the line 22 of Fig. 1,the two fig- 13 Claims. (Cl. 2647 ures showing alternativeconstructions. Fig. 3 is a fragmentary sectional view showing in greaterdetail a portion of the governor apparatus, the section being takenalong the line 3-3 of Fig. 2'. Fig. 4 is a transverse sectional viewbringing out in some detail a portion of the speed-droop apparatus, thesection being taken along the line 4-4 of Fig. 2'. tional view generallysimilar to Fig. 2 but showing a modified structure.

In the drawing A designates the casing structure of a hydraulicgovernor; B designates generally control mechanism for distributingpressure fluid for effecting changes in the fuel supply of thecontrolled engine in response to speed changes therein; and C designatesgenerally the speed-droop mechanism-that is, the apparatus forefi'ecting controlled variations in the speederspring tension as afunction of the loading of the engine being governed. While I shall, forthe sake of clarity, describe generally all the apparatus shown in thedrawing, I shall in the present specification devote particularattention to the apparatus generally designated C, since the other novelfeatures of the illustrated apparatus have been described at length andclaimed in my said copending application, Serial No. 655,086, filedMarch 18, 1946, and now Patent No. 2,571,842, of which this is adivision.

The casing A may be of any suitable construction. In the embodimentshown, it comprises a base plate 10, a frame structure It carried bysaid base plate, and a top dome l2 resting upon the body member ll. Domemember I2 is provided with a flange base l3 formed for registration withbody member i I and base ll]. The adjoining surfaces of the three casingelements are provided with gaskets I5 to make them proof against oilleakage, and they are suitably bolted together by bolts I4.

The dome casing I2 is provided in its topper- .tion with an annularshoulder I I which serves as a support for the ball head l8 whichcarries fly Weights 22. (As may be noted by comparison of the twofigures, the reference numerals in,

Figs. 2' and 2 are similar for corresponding ele- ,ments except that thereference numerals in Fig. 2 are given a prime designation. Thestructures shown in the two figures are functionally equivalent,representing alternative modifications of my speed-droop invention.) 1

The control mechanism 13 may be of any suitable type. In the form shownin Fig. 2', the fly weights 22 are pivoted on pins 23 to the ball head18 and are Provided with inwardly extend-* Fig. 5 is a fragmentary sec-'ing arms 24 having contact toes 25 turned downwardly. Toes 25 press uponthe upper race of a ball thrust bearing 4|, the lower race of whichrests upon the upper flange 39 of the pilot-valve sleeve 40. Valvesleeve 40 is slidably and rotatably carried within a cylindrical bore 33provided with suitably spaced inlet and outlet ports for the passage ofpressure fluid into and out of pivot valve 40.

Concentrically carried within sleeve 40 is a shaft 21 which functions asthe main governor drive shaft. Its outer end is equipped with a slot 28suitable for connecting it to the output shaft of the engine to begoverned, so that in operation shaft 21 rotates in synchronism with suchoutput shaft. Near its lower end shaft 21 is provided with an integralgear member 29 which serves as part of the gear pump to be describedhereinafter. Gear 29 rotates within a suitable pump chamber cut intobase member l l.

' Above gear member 29 shaft '2'! isprovided with a reduced-diameterportion which passes through valve sleeve 40 with substantial clearanceexceptat its uppermost end, where shaft?! is machin'ed 'to make a sealfit with sleeve All. The reduced-diameter zone just described is brokenup, however, by annular lands 3! and-32 which, in cooperation withsleeve 49, divide the interior of sleeve into three chambers.

The upper end of shaft 27 passes through the center of thrust bearing 4!and is received within and keyed to ball head I3, so that rotation ofshaft 21 accomplishes rotation of ball head [8 and of fly weights 22'.

Gear 291 cooperates with gear 52 to form a gear pump carried within thepum chamber cut into the bottom surface of body member I I. Hydraulicfluid at sump pressure may be provided for the pump chamber by anysuitable means. Rotation in the proper direction of the gears 29 and 52will cause fluid pressure to build up in port 65 extending upward fromthe pump chamber, and such'fiuid will be carried into the transversebore 6| shown in detail in Fig. 3. The maximum fluid pressure developedby the gear pump is under the control of the ball relief valve formed byvalve seat 63, ball 52, and spring 64, carried in one end of thetransverse bore 6|. A gland 53, screwed into a threaded zone in the endof bore 6|, serves as a stationary seat for spring 64. A passage 56provides external communication to the low-pressure side of valve 62 andmay be used to admit lubricating oil to the governor from the primemover lubricating pump. A vertical bore 59 connects the low-pressureside of valve 62' to the inlet portion of the gear-pump chamber. It willbe obvious to those familiar, with gear pumps that when the pressuredeveloped in bore 60 exceeds a critical value ball 62 willbe moved offits seat and oil will be allowed to bypass into bore 59 and bere-circulated.

The highs-pressure end of transverse bore 6| may be closed with asuitable threaded plug 51a. Since bore 6! and the elements of the arpump are symmetrically arranged, the relative positions of g1and53 andplug 57a may be reversed if necessary, according to the direction ofrotation of shaft 21. That is, if shaft 21 is in the direction whichwill produce high pressure in bore 59, then gland 53, ball 62, andspring 64 may be moved to the opposite end of transverse bore 6 I beinginterchanged with plug 51a.

A bore 46 carries the pressure fluid from the gear=pump to the pilotvalve, such fluid bein 7 medium to the prime'mover.

introduced into the central pilot-valve chamber 5| by means of ports 44and 45. Ports 4! cooperate with land 3| to provide control means forgoverning the flow of hydraulic fluid to and from a servomotor chamber50 (Fig. 4) through passage 49, communicating with chamber 50. Exhaustports 30 near the lower end of bore 33 provide an outlet to sump andthus maintain the zone below land 3! at sump pressure.

Supported within the chamber of the dome 12 between the fly weights 22is a frusto-conical speeder spring 35. The lower end of the spring 35rests upon an annular spring seat 36 having a cylindrical upwardextension 42 which is slidably carried on bushing 43, pressed into theupper end of bore 33. (Two other annular bushings, denoted ita and 43brespectively, are also pressed into bore 33 at spaced positions belowbushing 43, as may be seen in Fig. 2'. The machined cylindrical interiorsurfaces of these bushings cooperate with the outer surface of valvesleeve 49.)

The pilot-valve sleeve 49 is preferably formed of thin metal, so that itwill be'light in weight and easily moved longitudinally of the shaft 21.It is suspended from upper spring seat 31 by means of its flange 39resting on the shoulder 38, and which moves downwardly in response topressure exerted upon the ball thrust bearing 4! by the toes 25 of thefly-weight arms 24. It will be seen, therefore, that the position of thepilot valve is determined by the balance position at which thecentrifugal force developed by the fly weights and transmitted to thethrust bearing 4| balances the force exerted by the speeder spring 35.

In servomotor chamber 50 is a plunger 74, machined to fit snugly butslidably therewithin. Plunger it extends externally of the body memberII at its outer end and is provided with a forked outer terminal 15 forconnection to a control rod (not shown) connected to a fuel pump, mixingvalve, steam throttle, or other device for controlling the supply offuel or other energy Plunger "E4 is provided on its lower side with akeyway "H5 in which a key ll extends, the key being pressed in a holeprovided therefor in body member H, as shown in Fig. 4. Plunger i=3 isalso provided, above keyway it, with a vertical slot in which a cammember I3 is mounted for pivotal movement upwardly and downwardly uponpivot pin it. The upper surface of cam 18 bears upon the flat face of aflattened ball 80, which in turn supports a plunger 83 having its lowersurface machined to conform to the spherical surface of ball til.

The elevation of the cam member '13 is controlled by a threaded pin-8i,having an inwardly extending point engaging cam is and an externalslotted portion 82 adapted to be engaged by a screw driver for inward oroutward adjustment.

The upper end of plunger 83 receives another flattened ball 85, the fiatsurface of which bears against the lower surface of block member 69which, in turn, is pivoted to the casingby pin it.-

A fork member 85 has its bifurcated end portion extending around sleeve42 and engaging the under surface of spring seat 36. The shank portionof fork 86 is provided with a bos 51 secured by pin 68 to block member6?). A leaf spring 34a bears at all times downwardly upon block 69 andthus exerts a continuous downward pressure on cam 78, through ball 84,plunger 83, and ball 80.

A rotatable cam member H is carried within body member I I immediatelybelow fork 66, and is provided with a cylindrical shaft portion 72journalled into body member I I and extending externally, as shown inFig. 1. The outer end of shaft 12 may be provided with a slot 13 tofacilitate rotating it with a screw driver or other instrument. As maybe seen from Fig. 2', fork t rests on cam l! as a fulcrum, and theposition of spring seat 36 (thus the compression of spring may be variedby rotating shaft 12,

While the operation of the pilot-valve structure does not constitute apart of the present invention, I shall explain it briefly, for clarity,as follows: When the governed engine has been started, the speed atwhich it will stabilize will be determined by the compression of speederspring 35, and thus by the manually determined position of shaft 72.Initially, sleeve will be raised by spring 35 and pressure fluid willaccord ingly be admitted through port 4'1 and bore 49 into servo chamber50. This will result in outward movement of plunger 14 and consequentincrease in the supply of fuel or other energybearing material to thegoverned engine. As the engines speed increases responsively to thissupply of additional fuel, fly weights 22 will cause increasing pressureon bearing 4!, resulting in downward movement of sleeve 4i? until aposition of stabilization is reached at which the port 87 is inregistration with land 3!. then run at the stabilized speed until someevent, such as a change in load, occurs to make it speed' up or slowdown. If it should speed up, sleeve 40 will be pressed downwardly beyondits equilibrium position and some of the pressure fluid contained withinservo chamber will be allowed to escape via bore 49 and sump ports 35.This will result in an inward movement of plunger 14 and consequentreduction in the fuel supply to the governed engine. (Plunger is isexternally spring loaded (not shown) so that the spring tends to movethe servo plunger inwardly to fuel-off position.)

Should the change in load cause the engine speed to decrease, the forceof spring 35 will cause the sleeve 40 to rise, thus admitting additionalpressure fluid to bore 49 from chamber 5!, causing the servo plunger 14to move further outward and thus increase further the engine fuelsupply.

The present invention relates particularly to the means herein providedfor producing speed droop, that is, for causing the speed of the engineto go down to a desired degree as the load on it increases. That resultis accomplished in the Fig. 2 form of the invention by the apparatus,just described, involving the plunger 8.3 and the cam 18. When, as aresult of increasing load, the plunger 14 moves outward, cam 78 causesplunger 83 to rise, and the position, therefore, of pivot pin 63 is alsocaused to move upward. As a result, fork member 66, turning on cam H asa fulcrum, permits spring seat 36 to move downward, with a resultingreduction in the com pression of spring 35. This movement causes theengine to stabilize at a speed somewhat lower than it formerly had. Thequantity of speed reduction for a given change in load is within thecontrol of the operator by means of adjustment of pin 8 l As I haveheretofore mentioned, Fig. 2 shows apparatus generally similar to Fig. 1except that I have therein shown a modified form of my speed-droopapparatus. In that structure, I have provided, as a manual speed-controldevice, a

The engine will Til shaft 12, journalled in the casing member II" forexternal manual rotation, as with shaft 12 in the Fig. 2 embodiment. Onits inner end, shaft 12 has a flattened surface carrying cam 91, bearingupon a bent bifurcated arm 89 which presses on the underside of springseat 36'. The opposite end of arm 89 is secured to a ball-like member 84the spherical surface of which is received within a suitably formed seatin the upper end of plunger 83'. Plunger 83 is actuated by cam 18 in thesame manner heretofore described with respect to plunger 83 in the Fig.2 embodiment. Manual speed control in the Fig. 2 form of the inventionis accomplished by rotation of shaft 12, which raises or lowers arm 89and thus raises or lowers spring seat 36. The position of spring seat36' and the compression of speeder spring 35 are modified by changes inthe position of plunger :4 by the raising or lowering of member 34' byway of plunger 83' and flattened ball Fig. 5 shows a slight modificationof the Fig. 2 structure in which upper ball member 84' is dispensed withand the plunger 83 is replaced by a plunger 83a having its upper endmodified to provide a pivot pin 68, on which the inner end of arm 89 ispivoted; The operation of the Fig. 5structure is similar to that of theFig. 2 structure except that the pivoting action around pin 63 issubstituted for the rotation within its seat of ball member fil' as theplunger is raised and lowered.

While I have in the present specification described in considerabledetail certain specific embodiments of my invention, it is to beunderstood that those are illustrative only, and that the scope of myinvention is not limited thereto but is to be determined primarily withreference to the appended claims.

I claim:

1. In governor mechanism of the type wherein the movement of a fluidservo-motor adjusts the speed of a prime mover and a control mechanismfor moving said servo-motor is responsive to the loading of a speederspring in the control operation, apparatus for automatically changingthe loading of the speeder spring during movement of the servo-motor,comprising a seat for said speeder spring, an elongated speed loadcontrol member engaging at one end said speeder spring and beingpivotally connected at its other end to a pivotally-mounted supportingblock, a fulcrum for said control member intermediate the ends thereof,a cam carried by said servomotor, and cam follower means fortransferring the force movement of said cam to change the position ofthe pivotal connection of said control member and said block to changethe loading of said speeder spring.

2. The structure of claim 1 in which said fulcrum is a cam adjustablymounted to provide a loading control for said speeder spring independentof the cam loading of said spring.

3. In speed governor mechanism of the type wherein the movement of afluid servo-motor adjusts the speed of a prime mover and a controlmechanism for moving said servo-motor is responsive to the loading of aspeeder spring in the control operation, apparatus for automaticallychanging the loading of the speeder spring during movement of theservo-motor, comprising a seat for said speeder spring, an elongatedlever engaging at one end said speeder spring and being pivotallyconnected at its other end to a pivotally-mounted supporting block, anadacmzsu justable cam intermediate the ends of said lever and providinga fulcrum therefor, a cam carried by the piston of said servo-motor andadapted to move therewith, aslidably-mounted plug extending between thepivotally-connected end of said lever and said second-mentioned cam andadapted to change the position of the pivotal connection of said leverand said block to change the loading of said speeder spring, andmeansfor urging the pivotally-connected end of said lever and said block intoengagement with said second-mentioned cam.

4. The structure of claim 3 wherein the cam carried by the piston orsaid servo-motor is adiustably carried thereby, and amanually-adjustable pin carried by the piston of said servomotor isadapted to adjust the cam.

5. In a hydraulic speed-control governor for engines, a servo pistonadapted upon movement to vary the speed setting of the engine, a speederspring adapted upon changes of the loading thereof to actuate said servopiston, means arranged with said servo piston and said speeder spring tomove said servo piston in response to changes in the loading' of saidspring, a seat for said speeder spring, a lever engaging at one end saidspring seat and being pivotally connected at its other end to apivotally-mounted supporting block, means for changing the speed settingor said governor comprising a rotatably-mounted cam providing a fulcrumfor said lever intermediate the ends thereof whereby movement of saidcam changes the loading of said speeder spring, and speed droopapparatus including a servo cam adjustably carried by the piston of saidservomotor, a cam follower extending between said servo cam and thepivotally connected end of said lever and adapted upon movement of saidcam to change the position of the pivotallyconnected end of said leverto vary the loading of said speeder spring, and spring means for biasingsaid cam follower against said servo cam and the pivotally-connected endof said lever against said cam follower.

6. The structure of claim 5 wherein said cam follower comprises aslidably-mounted plunger having at each end a ball seat,'and a ball ineach of said seats engaging said lever and said servo cam, the ballengaging said servo cam having a flattened surface portion adapted toride upon the cam surface of the servo cam.

'7. In control apparatus, a control member, an axially movable memberresponsive to conditions imposed thereon by the control member and beingmovable in response to such conditions to H control mechanism arrangedtherewith, a cam carried by said axially movable member, a lever 8coupled to said control member and being adjustably positionable tochange the state of said control member and thereby change conditionsimposed by said control member upon said movable member, and a camfollower in engagement with said cam and being coupled to said lever foradjusting said lever in accordance with the position of said cam, saidcam follower comprising a plunger having at least at one end thereof aball seat and at its other end being coupled to said lever in anarrangement whereby movement'of said plunger changes the position of thelever, and a ball in said seat and in engagement with said cam.

8. The structure of claim 7 wherein said plunger is equipped at each endwith a ball seat, and a ball is mounted in the second seat and is inengagement with said lever.

9. The structure of claim 8 wherein at least one of said balls isprovided with a flattened engaging surface.

10. The structure of claim '7 wherein said plunger at the end thereofcoupled to said lever is pivotally connected thereto.

11. In governor apparatus, a speeder spring, a servo piston in operativearrangement with said speeder spring and movable in response tocondition changes imposed thereby, and speed droop apparatus comprisinga lever engaging said speeder spring and being adjustably mountedadjacent one end thereof, a cam carried by said servo piston, a plungermounted between said cam and lever for movement therebetween and havingat each end a ball seat, and a ball in each of said seats, one of saidballs being in engagement with said lever and the other of said ballsbeing in engagement with said cam.

12. The structure of claim 11 in which said lever engages at an endthereof said speeder spring.

13. The structure of claim 11 in which said lever engages said speederspring intermediate the ends of the spring, and an adjustable cam inoperative arrangement with said lever at the end thereof most remotefrom the adjustably mounted end provides manual adjustment of thetension in said speeder spring.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,267,919 Hoof Dec. 30, 1941 2,268,230 Warner Dec. 30, 19412,364,115 Whitehead Dec. 5, 1944 2,565,041 Parker Aug. 21, 1951

